复杂材料体系的第一原理研究

对复杂材料体系进行量子力学的从头计算一睦是材料和物理科学重要方向。采用密度泛函理论和第一原理赝势法，我们对经下一些复杂的体系进行了研究，包括：1）计算了铝中锂，硅，镁等重要杂质的形成能，说明了这睦杂质形成替位的可能性；2）研究了过渡金属W，Mo和Nb（001）表面在外加电场下的表面基态结构的改变。发现了W（001）和Mo（001）表面的基态结构随着电场的增强而相变，而Nb(001）表面的结构却不会改变；3）从第一原理的角度研究了由Al12X(X=C,Si,Ge)原子集团构成晶体的可能性，指出通过A112X集团立方密堆积的方法来构造半导体是不合适的；4）计算了一系列过渡金属在Al(001)表面上的吸附，发现Pt,Au吸附时的：“反常”功函数变化行为。

First-principles Studies on Some Complex Materials

First-principles studies on the complex materials are of great interests in both the material science and physics. We present in this paper ab initio studies on some complex material systems based on the density functional theory and first-principles pseudo-potential method. Systems studied are: 1) the formation energies of point defects of Li, Si and Mg in metal Al. The possibilities of forming substitutional point defects are shown; 2) change of ground state of W,Mo, and Nb(001) surfaces induced by external electric field. Ground state changes have been found on both the W(001) and Mo(001) surfaces, however, Nb(001) ground state is not field dependent; 3) the possibilities of forming cluster solids by assembling Al12X (X=C,Si,Ge) clusters. Our ab initio calculations show that crystal composed of FCC-Al12X clusters will be a metal rather than a semiconductor ; 4) the interaction of transition metals Pd,Pt, Ag and Au with the Al(001) surface. An "anomalous" work function behavior of Pt and Au adsorption on Al(001)surface relative to other members of transition matals has been found.